OK, What's the Final Verdict on Class D?

[kittyboy]

I would think the market will continue to get smaller and smaller for the more traditional, lead sled type amps. I just got a report from a TB friend who has ears I trust, and he said the new Markbass SD1200 is just a slammin' hammer, and more like a big honkin' F1 than a slightly more powerful SD800. You will be seeing more and more true 'lead sled' capable executions in the ultra light category IMO.

And... having recently played a 750x provided as backline, that is a classic case of a very large, very heavy amp that does not at all justify the size and weight given the output. Most of the current batch of 500 to 600 watt micro's will EASILY keep up with that one IMO and IME.

A DB750... well.... maybe not the Micro's, but I have a feeling the 10 pound Carvin B2000 would give it MORE than a run for its money.

omg that b2000 looks FEROCIOUS...and for $700 new?


Does anyone know if the B2000 can be EQ'd relatively flat, for use in a PA application with a little mixer?

 

[Walking]

omg that b2000 looks FEROCIOUS...and for $700 new?


Does anyone know if the B2000 can be EQ'd relatively flat, for use in a PA application with a little mixer?

Carvin has pa amps with the same technology, and these are cheaper than the bass amps per watt. Ditto with crown and others.

 

[Walking]

Sure there is. They have very clear technical, non-imaginary, bench-provable differences in sound (and reliability, shock resistance, etc.) from solid-state amps....

Tone is a very personal matter, but I'm gonna have to go ahead and disagree with you on the reliability and shock resistance. My experience is they don't like to be dropped nearly as much as solid state...

 

[kittyboy]

Carvin has pa amps with the same technology, and these are cheaper than the bass amps per watt. Ditto with crown and others.

Thanks. It would be nice however to be able to plug right into a B2000 one night, and the next night run a portable mixer through it for PA duty...

So: is the default eq on the b2000 flat, or can flatness be achieved?

 

[Bassmec]

Sure there is. They have very clear technical, non-imaginary, bench-provable differences in sound (and reliability, shock resistance, etc.) from solid-state amps.

That's the question I'm asking here -- are class Ds equal or superior in purely technical terms to conventional solid-states, or not, and if not, why? -- and so far have pretty much wasted my time.

To be perfectly honest the question is a waste of your time and mine because its all subjective, but if your asking weather a class d markbass amp rig sounds like a neve 1073 pre into a krell class a power amp with atc soft dome monitors, the answer is you get what you pay for.
But I would substitute this:
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for the trany power amp and this for the 1073 tranny pre:

If I where to chose an eq it would be this:
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Class D amps don't suck but there is stuff out there in solid state that has marinair transformers in the circuits and we humans like marinar and other audio transformers interspersed in our circuits for some odd reason, probably mainly for the natural compression they exhibit when driven near saturation.
PS It go's to twenty man!

 

[Walking]

Thanks. It would be nice however to be able to plug right into a B2000 one night, and the next night run a portable mixer through it for PA duty...

So: is the default eq on the b2000 flat, or can flatness be achieved?

Don't know. Bet carvin would like to discuss it with you, though.

Yeah, the weight of that audio research would make my old ashly seem like it was class D.

 

[Bongolation]

I'm gonna have to go ahead and disagree with you on the reliability and shock resistance. My experience is they don't like to be dropped nearly as much as solid state...

That's what I said.

 

[tombowlus]

So: is the default eq on the b2000 flat, or can flatness be achieved?

We achieved a fairly flat response out of the B1500 we tested in issue #2, and although the B2000 is EQ'd a little differently, my guess is that it can get fairly close to flat, as well. FWIW, here are the settings we used for our "optimally flat" graph on the B1500:

And here was our "optimally flat" response curve:

 

[GeoffB]

I have a '69 SVT, Kartke 7000 and a LMII (since 2008). For regular bar gigs, the LMII is fantastic.

Since it looks and feels more like a radio than an amp, I was carrying it around in a backpack style bag. The zipper failed and the amp fell about 12" onto asphalt.

Dead.

Can't find a service center in the States. Sent an e-mail to MB. They referred me to GC. GC did not reply for a week until after I bitched. They referred my to a service center in Mass. Those people haven't replied either.

So in my experience, They are great. Sound nice. Built to be dispoasble.

Anybody wanna buy a blue line SVT?

 

[cassanova]

thank god for that! btw, i am 100% positive that i could tell an svt from any other amp if i'm playing it. any fool could. and my gear is up onstage for me. it isn't up there for the audience...it's up there for me.

Oh I agree, my gears up there for me as well.

i really don't care if anyone else can tell the difference between my svt and a hartke 3500. i can, and that's good enough.

This is why I don't like using blind tests as examples. Because nobody really ever cares if anyone can tell the difference or not. We all buy what we like regardless of what others think or say.

 

[JimmyM]

This is why I don't like using blind tests as examples. Because nobody really ever cares if anyone can tell the difference or not. We all buy what we like regardless of what others think or say.

exactly. and then we all bitch at everyone else for not liking what we like

 

[Doc Halo]

The primary difference between the iAmp800 and the LMII/III is failure rate and problems (noise, etc.). And, it is not in the direction that price would suggest (I am a former iAmp owner by the way).

Thanks, Ken. Aside from that one production run with the counterfeit caps, I wasn't aware of any problems with the iAmp 800. (I've had mine for years, it hasn't given me a lick of trouble.) My point was that in the event of component failure, the iAmp was designed to be fixed, not thrown away. And to be fair, the iAmp has been around for about twice as long as the LMII, although neither was around for very long before something new came along!

--Dean

 

[KJung]

Thanks, Ken. Aside from that one production run with the counterfeit caps, I wasn't aware of any problems with the iAmp 800. (I've had mine for years, it hasn't given me a lick of trouble.) My point was that in the event of component failure, the iAmp was designed to be fixed, not thrown away. And to be fair, the iAmp has been around for about twice as long as the LMII, although neither was around for very long before something new came along!

--Dean

Even the most problematic products still have a high percent of units that don't have any problems. It is all about failure rate. Even the worst products probably only have a 10% failure rate, but that is just way too high.

Anyway, of course, the easiest to fix amps are ones that you just swap the board out. The question is, will the company make that a cost effective way to fix an older unit. Of course, with a well designed product, less than 1 in 100 owners should have a problem within the reasonable life expectancy of an amp (10 years, 15 years?). However, it is still an issue that I'm sure some would be concerned about.

 

[kittyboy]

That's super-helpful Tom; thanks.

Have you reviewed the B2000 yet?

And btw, did you ever do a frequency chart on the walkabout head, or on acoustic image Focus head? Wondering how flat they can get...

We achieved a fairly flat response out of the B1500 we tested in issue #2, and although the B2000 is EQ'd a little differently, my guess is that it can get fairly close to flat, as well. FWIW, here are the settings we used for our "optimally flat" graph on the B1500:

And here was our "optimally flat" response curve:

 

[tombowlus]

That's super-helpful Tom; thanks.

Happy to help!

Have you reviewed the B2000 yet?

Not yet, but we do hope to get one in for review (as an update to the B1500 review).

And btw, did you ever do a frequency chart on the walkabout head, or on acoustic image Focus head? Wondering how flat they can get...

Not yet. FWIW, so far, the most "flat" amp we have tested is the Phil Jones M-300. That head is amazingly flat.

Tom.

 

[fourstringburn]

I think some of you are missing the beauty of class D amps. While some have given these technical formulas why they can or can't, they are forgetting class D amps seems to break ohms laws and traditional train of thought due to it's design. The spec's are real as I tested it myself (at least the amperage draw ). My class D amp will put out up to 3000 watts and use only 7 or so amps and weigh less than 45lbs and are efficient. Sorry if that goes against your engineering degree but I play them not design them. Rock on...

 

[dponbass]

I have worked in different small and large music retailers and my experience as far as reliability has been it much less about what kind of power section or power class they are and much more about design and manufacturer reputation. By that I mean, I see many different repairs needed to certain brands that I will not name but have been named in this thread in every product/model they make due to low quality parts used. I think brand reputation is a far better indicator of long term reliability than what class power they use. I don't think we'll have a world-wide class d failure in the year 2012 or any other year for that matter. I could envision brand x's model z failing all in that year though because of the crap parts used. If I look at new gear, I try to find repair men's advice on reliability of that amp because they will tell you the honest truth, like how that same brand x has kept them fed over the last 20 years and that they will always have job security as long as they are made.
One thing I find interesting and I think this hits on the originator's point of weight=quality? but is the Aguilar AG500 a better amp than the Genz Benz Shuttle 9.0? Both are class D, but the GB is 4 lbs and the AG is almost 20? It's just a mear example, and frankly I think they are both great amps, but I think the point was will the AG be more reliable because it weighs more? Perhaps have better parts? I think the answer to this example should come from whether you trust Aguilar or Genz Benz more. I hope that helps, or at least that's how I view this type of question.

 

[KJung]

I have worked in different small and large music retailers and my experience as far as reliability has been it much less about what kind of power section or power class they are and much more about design and manufacturer reputation. By that I mean, I see many different repairs needed to certain brands that I will not name but have been named in this thread in every product/model they make due to low quality parts used. I think brand reputation is a far better indicator of long term reliability than what class power they use. I don't think we'll have a world-wide class d failure in the year 2012 or any other year for that matter. I could envision brand x's model z failing all in that year though because of the crap parts used. If I look at new gear, I try to find repair men's advice on reliability of that amp because they will tell you the honest truth, like how that same brand x has kept them fed over the last 20 years and that they will always have job security as long as they are made.
One thing I find interesting and I think this hits on the originator's point of weight=quality? but is the Aguilar AG500 a better amp than the Genz Benz Shuttle 9.0? Both are class D, but the GB is 4 lbs and the AG is almost 20? It's just a mear example, and frankly I think they are both great amps, but I think the point was will the AG be more reliable because it weighs more? Perhaps have better parts? I think the answer to this example should come from whether you trust Aguilar or Genz Benz more. I hope that helps, or at least that's how I view this type of question.

Your example is another good one of why 'class of amp' is a zero issue. The difference between 'regular sized' amps and 'micro' amps is primarily defined by the type of power supply (traditional, toriodal or SMPS). There are larger, heavier amps using class D amps, and there are micro's using class A/B amps. The primary difference is the power supply type.

 

[unclekebm]

I got a 55lb rig that's as 'loud, warm, thick, punchy & articulate as I've ever had or will ever need ~

verdict? - I am one happy camper " )

 

[johnk_10]

My class D amp will put out up to 3000 watts and use only 7 or so amps and weigh less than 45lbs and are efficient. Sorry if that goes against your engineering degree but I play them not design them.

again, your Crest's specs says that CD3000 draws 7 amps a 1/8 of its rated power output, and at around 45 lbs, and althugh i think that its a great amp, i wouldn't consider it to be a 'lightweight' amp by today's standards.

the Crown xti4000 (4000watts) is 21.5lbs, their new XLS drivecore series XLS2500 (2400watts) is 15.8 lbs, and Peavey's new IPR series, are what i consider to be true lightweight high-powered power amps.

i currently use Crown xti2000's (18.5 lbs) and they are more than capable at getting the job done. i also have a couple of XLS1500's on order that will be arriving soon that weigh only 8.6 lbs.